A horse appeared. It was midnight black and not glossy; it was hard to see at all. It trotted toward them purposefully.

Suddenly Chex was dreaming. In her dream a jet-black centaur mare appeared. "What are you doing here in my retreat?" she demanded.

Astonished, Chex could only answer "Who are you?"

"I am Mare Nectaris, and this is the Sea of Nectar, where I relax between deliveries. You are tracking it up!"

"You're a night mare!" Chex exclaimed.

"Of course. And you are out of your pasture, aren't you?"

"I'm Chex Centaur, and I was trying to fly to Mount Rushmost, but Fracto, the evil cloud, blocked my way, and I had to detour—"

"Fracto! No wonder! My cheese is all gooky from the last time he rained on it! And the moon is supposed to be dry. He has no respect at all."

"That's right," Chex agreed. "I have an urgent mission, and he—"

"Very well, I can see it's not your fault. Come over here to my fountain and wash off your hooves."

Then Chex snapped awake, and saw the black mare leading the way to a much smaller disk, where water squirted up. Relieved, she followed.

The fountain was big enough so that Chex was able to stand in it and get her feet entirely clean. Beyond was a region where the cheese was dry and hard, probably sun-baked Cheddar, so she could walk on it without getting gunked. "Thank you so much, Mare Nectaris," she said. "I really am sorry I landed in your cheese. I need to move on as quickly as I can."

She looked up. One of the odd things about the moon was that it made Xanth seem up instead of down. Probably that was more of the magic of perspective. But there was Fracto, staying right between her and Mount Rushmost. He wasn't going to let her get through without a hassle.

The dream reappeared. "We don't like Fracto," the black centaur lady said. "He tries to interfere with our delivery of bad dreams. He can't touch us physically, of course, but he fogs everything up so it's hard for us to see where we're going. That puts us behind schedule, so that the dreams may be delivered late in the night, and sometimes folk even wake up and remember them. That is bad form, and we get the blame."

"I suppose there's nothing you can do about it," Chex said, worrying about how long it would be before she could get through to Cheiron. If only Fracto hadn't picked this occasion to get difficult! That was his magic: to appear at the very worst time for anyone else. How absolutely maddening it was to be stuck here like this, unable to get around the evil cloud! "I wish you could give him a bad dream!"

Mare Nectaris was so surprised that the dream dissolved. But in a moment it reappeared. "I wonder if we could? That would be a dream come true, if you will pardon the expression."